Sub-Report Data Not Displayed

I have created a report/sub-report combination in SSRS 2005.
When I preview the combination within Visual Studio using the Preview tab, the report and appropriate sub-report data are displayed and printed.
After deploying both the report and sub-report, I am attempting to run the report out of Report Manager.
When I run the main report with parameters that should generate a sub-report as well, no sub-report is displayed. I can sucessfully run the sub-report by itself within Report Manager using the parameters from my main report.
What did I miss in the sub-report design?

check whether you are passing correct values.
you can put those passing values to a text box and verify whether you are passing correct value. For example if you want to pass AA as a parameter , it should be A not "A" at subreport parameters